Optical modulator, optical device and projector

ABSTRACT

A liquid crystal panel ( 441 ) has an optical modulator body ( 500 ), an accommodating portion ( 511 ) for accommodating the optical modulator body ( 500 ), a holding frame ( 510 ) for pressing and holding the optical modulator body ( 500 ) against the accommodating portion ( 511 ), and a frame member ( 512 C) made of heat-conductive material and interposed between the optical modulator body ( 500 ) and a fixing plate ( 512 ), the frame member ( 512 C) being provided on an outer periphery of a first substrate ( 501 A) of a pair of substrates ( 501 A,  501 B) disposed on the side of the fixing plate ( 512 ), the fixing plate ( 512 ) and the frame member ( 512 C) being integrally formed.

BACKGROUND OF THE INVENTION

[0001] 1.Field of the Invention

[0002] The present invention relates to an optical modulator formodulating a light beam irradiated by a light source in accordance withimage information, and an optical device and a projector having theoptical modulator.

[0003] 2.Description of Related Art

[0004] Conventionally, a projector having a light source, an opticaldevice for modulating a light beam irradiated by the light source inaccordance with image information and a projection optical system forenlarging and projecting the light beam modulated by the optical devicehas been known as an optical equipment using an optical device (seeJapanese Patent Laid-Open Publication No. 2000-89364).

[0005] The optical device of the projector has three optical modulatorsfor modulating color light in accordance with image information, and acolor combining optical system for combining respective light beamsmodulated by the optical modulators to form an optical image.

[0006] The optical modulator has an optical modulator body having a pairof substrates sealing an electrooptic material such as liquid crystaltherebetween and a holding frame for accommodating and holding theoptical modulator body.

[0007] The pair of substrates of the optical modulator body includes afirst substrate on which a data line, a scan line, a switching element,a picture electrode etc. for applying driving voltage to theelectrooptic material are formed, and a second substrate on which acommon electrode, a black mask, and a color filter as necessary areformed.

[0008] The holding frame has an accommodating portion for accommodatingthe optical modulator body, and a fixing plate for positioning theoptical modulator body inside the accommodating portion. The opticalmodulator body is accommodated in the holding frame with one of thesubstrates facing to the side of the accommodating portion of theholding frame and, subsequently, the optical modulator body is pressedby the fixing plate from the side of the other substrate.

[0009] In such optical modulator, the data line and scan line formed onthe first substrate and the black mask formed on the second substrateetc. absorbs the heat generated by irradiating the light beam from thelight source, thereby raising the temperature of the first and thesecond substrates. Accordingly, the heat of the substrates has to bereleased.

[0010] The substrate disposed on the accommodating portion side contactswith the accommodating portion on a large area, the heat can beefficiently released by constructing the accommodating portion with aheat-conductive material such as metal.

[0011] However, heat of the substrate located on the side of the fixingplate cannot be efficiently released, because the fixing plate isconstructed by a thin plate and therefore has small heat capacity andthe fixing plate only partially contacts with the substrate to press andhold the substrate.

[0012] Though it is possible to thicken the fixing plate to increase theheat capacity of the fixing plate, such arrangement inevitably increasesthe thickness of the optical modulator and the size of the opticaldevice provided with the optical modulator, so that size reductioncannot be achieved. Further, since the gap against an optical elementdisposed on the downstream of the optical modulator such as apolarization plate is enlarged, image quality such as color evenness andcontrast may be deteriorated.

SUMMARY OF THE INVENTION

[0013] An object of the present invention is to provide an opticalmodulator without deteriorating image quality and capable of improvingheat releasing ability of the substrate, an optical device and aprojector having the optical modulator.

[0014] An optical modulator according to an aspect of the presentinvention modulates a light beam irradiated by a light source inaccordance with image information, the optical modulator including: anoptical modulator body having a pair of transparent substrates betweenwhich an electrooptic material is sealed; a holding frame having anaccommodating portion that accommodates the optical modulator body and afixing plate that presses and holds the optical modulator body withinthe accommodating portion; and a frame member made of a heat-conductivematerial and provided on an outer periphery of a first substrate of thepair of substrates disposed on the side of the fixing plate, the framemember being in contact with the accommodating portion and/or the fixingplate.

[0015] The frame member may only be in contact with the accommodatingportion of the holding frame or may only be in contact with the fixingplate. Alternatively, the frame member may be in contact with both ofthe accommodating portion and the fixing plate.

[0016] According to the above arrangement, since the frame member madeof heat-conductive material is disposed on the outer periphery of thefist substrate of the optical modulator, the heat of the first substratecan be efficiently transferred to the frame member. Since the framemember is in contact with the holding frame, the heat transferred to theframe member is released to the outside through the holding frame. Theprovision of the frame member made of heat-conductive material allowsefficient heat releasing from the first substrate to the holding frame,thus enhancing heat-releasing ability of the first substrate.

[0017] Further, since excellent heat-releasing ability can be obtainedby providing the frame member, there is no need for increasing thethickness of the fixing plate in order to increase the heat capacity ofthe fixing plate, thus avoiding deterioration of image quality.

[0018] In the optical modulator of the above aspect of the presentinvention, the fixing plate and the frame member may preferably beintegrally formed.

[0019] The fixing plate and the frame member may be integrated afterconstructing separate components and bonding the components with anadhesive etc. or may be integrated by welding etc. Alternatively, thefixing plate and the frame member may be an integrated molding formed byinjection molding process etc.

[0020] According to the above arrangement, since the frame member madeof heat-conductive material is disposed on the outer periphery of thefirst substrate of the optical modulator, the heat generated on thefirst substrate can be efficiently transferred to the frame member.Further, since the frame member is formed integrally with the fixingplate, sufficient contact area between the frame member and the fixingplate can be secured, thus releasing the heat generated on the firstsubstrate toward the outside through a heat conduction channel from theframe member to the fixing plate. Accordingly, heat-releasing ability ofthe optical modulator body can be improved, thus lengthening the life ofthe optical modulator. Further, since the heat-releasing ability of theoptical modulator body can be enhanced, there is no need for increasingthe thickness of the fixing plate to increase the heat capacity of thefixing plate, thus avoiding deterioration of image quality.

[0021] In the optical modulator of the above aspect of the presentinvention, the fixing plate and the frame member may preferably be madeof a heat-conductive metal or a heat-conductive resin.

[0022] The heat-conductive metal may be steel-nickel alloy such as Invarand 42Ni−Fe, magnesium alloy and aluminum alloy.

[0023] The heat-conductive resin may be a resin (polycarbonate,polyphenylene sulfide, liquid crystal resin etc.) containing carbonfiller such as carbon fiber and carbon nanotube.

[0024] According to the above arrangement, since the fixing plate andthe frame member are made of heat-conductive metal or heat-conductiveresin having excellent heat conductivity, the heat-releasing ability ofthe first substrate can be further enhanced by the heat conductionchannel.

[0025] In the optical modulator according to the above aspect of thepresent invention, the thermal conductivity of the heat-conductive metaland the heat-conductive resin may preferably be not less than 10W/(m·K).

[0026] According to the above arrangement, the heat generated on thefirst substrate can be rapidly released through the heat conductionchannel. Further, the material of the fixing plate and the frame membercan be freely selected as long as the thermal conductivity thereof isnot less than 10W/(m·K), so that the most appropriate material can beselected in designing the optical modulator in accordance with requiredperformance etc.

[0027] In the optical modulator according to the above aspect of thepresent invention, the frame member may preferably be accommodated andheld in the accommodating portion together with the optical modulatorbody and a predetermined gap may preferably be secured between the outercircumference of the frame member and the inner circumference of theaccommodating portion.

[0028] According to the above aspect of the present invention, since apredetermined gap is secured between the outer circumference of theframe member and the inner circumference of the accommodating portion,mechanical interference generated between the frame member and theaccommodating portion on account of difference in thermal expansioncaused by different thermal expansion rate can be prevented even whenthe frame member and the accommodating portion are made of differentcomponents. Accordingly, distortion generated on the optical modulatoron account of the heat generated on the optical modulator body can beavoided, thus preventing deterioration in image quality on account ofchange in the shape of the electrooptic material sealed between the pairof substrates.

[0029] In the optical modulator according to the above aspect of thepresent invention, a dust-proof glass that prevents adhesion of dust onthe outer surface of the substrate may preferably be closely attached onthe outer surface of the first substrate, and the frame member maypreferably be in contact with the dust-proof glass and/or the firstsubstrate.

[0030] The frame member may only be in contact with one of thedust-proof glass and the first substrate, or may be in contact with bothof the dust-proof glass and the first substrate.

[0031] According to the above arrangement, when the frame member is onlyin contact with the first substrate, since the heat of the firstsubstrate can be directly transferred to the frame member, the heat ofthe first substrate can be efficiently released.

[0032] Further, when the frame member is only in contact with thedust-proof glass, the heat of the first substrate is transferred to theframe member through the dust-proof glass and is released through theheat conduction channel. Since the frame member is made ofheat-conductive material, the heat can be efficiently transferred fromthe dust-proof glass to the frame member. Accordingly, even when theframe member is only in contact with the dust-proof glass, excellentheat-releasing ability of the first substrate can be obtained.

[0033] When the frame member is in contact with both of the dust-proofglass and the first substrate, since the heat can be transferred fromboth of the dust-proof glass and the first substrate to the framemember, the heat-releasing ability of the first substrate can be furtherenhanced.

[0034] In the optical modulator according to the above aspect of thepresent invention, the dust-proof glass may preferably be made of anyone of materials selected from the group consisting of sapphire, quartz,crystal or fluorite.

[0035] According to the above arrangement, high thermal conductivity canbe applied to the dust-proof glass made of light-transmissive material.Accordingly, the heat-releasing ability of the first substrate can beenhanced by arranging the dust-proof glass with such material.

[0036] In the optical modulator according to the above aspect of thepresent invention, a heat-conductive adhesive may preferably be filledin the predetermined gap and between the frame member and the dust-proofglass and/or the first substrate.

[0037] According to the above arrangement, since the heat-conductiveadhesive is filled in the gap formed between the outer circumference ofthe frame member and the inner circumference of the accommodatingportion, the adhesive assists heat transfer between the respectivecomponents, so that heat conduction channel from the frame member to theaccommodating portion as well as the heat conduction channel from theframe member to the fixing plate can be secured, thus further improvingheat-releasing ability of the first substrate.

[0038] Further, since the adhesive having thermal conductivity is filledbetween the frame member and the dust-proof glass and/or the firstsubstrate, the adhesive assists heat transfer between the respectivecomponents, so that the heat generated on the first substrate can befurther rapidly released through the heat conduction channel from theframe member to the fixing plate.

[0039] In the optical modulator according to the above aspect of thepresent invention, the adhesive may preferably contain a metal material.

[0040] According to the above arrangement, since the metal materialthermally couples the components when the adhesive is sandwiched betweenthe components, heat transfer between the components can be furtheraccelerated.

[0041] In the optical modulator according to the above aspect of thepresent invention, a linear expansion coefficient of the fixing plateand the frame member may preferably be not more than 6*10⁻⁶/K.

[0042] According to the above arrangement, since the linear expansioncoefficient of the fixing plate and the frame member becomes close tothe linear expansion coefficient of the dust-proof glass and/or thefirst substrate, variation in dimension (expansion and contraction) ofthe fixing plate and the frame member and the dust-proof glass and/orthe first substrate caused by heat can be made approximately equal.Accordingly, when the fixing plate and the frame member are fixed to thedust-proof glass and/or the first substrate by an adhesive, distortiongenerated on the optical modulator on account of change in the dimensionof the respective components can be prevented, and deterioration inimage quality on account of change in the shape of the electroopticmaterial sealed between the pair of substrates can be avoided.

[0043] In the optical modulator according to the above aspect of thepresent invention, the plurality of data lines arranged mutually inparallel, a plurality of scan lines arranged in a direction orthogonalwith the plurality of data lines, a picture electrode, and a switchingelement disposed between the data and the scan lines and the pictureelectrode may preferably be formed on the first substrate.

[0044] Such scan lines and data lines are likely to absorb the heatgenerated by irradiating the light beam from the light source and thetemperature of the substrate with the scan lines and the data linesformed thereon is easy to rise.

[0045] According to the above arrangement, since the fixing plateintegrated with the frame member is located on the side of the firstsubstrate, the heat generated on the optical modulator body can beefficiently released.

[0046] In the optical modulator according to the above aspect of thepresent invention, the first substrate may preferably be disposed on alight-irradiation side of the optical modulator body.

[0047] Since polarization plate located on the downstream of the opticalmodulator and prism are attached on the light irradiation side of theoptical modulator body, heat-releasing ability of the light-irradiationside is inferior.

[0048] According to the above arrangement, since the fixing plateintegrated with the frame member is located on the side of the firstsubstrate located on the light-irradiation side, the heat-releasingability can be enhanced.

[0049] An optical device according to another aspect of the presentinvention has: a plurality of optical modulators that modulates aplurality of color lights in accordance with image informationrespectively for the color lights; and a color combining optical devicethat combines the color lights modulated by the respective opticalmodulators, in which the optical modulator is the above-describedoptical modulator.

[0050] According to the above aspect of the present invention, since theoptical device has the above-described optical modulator, the sameeffects and advantages as the above-described optical modulator can beobtained. In other words, an optical device causing no deterioration inimage quality and having excellent heat-releasing ability from thesubstrate can be provided.

[0051] A projector according to still another aspect of the presentinvention forms an optical image by enlarging and projecting a lightbeam irradiated by a light source after modulating the light beam, theprojector having the above-described optical modulator or theabove-described optical device.

[0052] According to the above arrangement, the same effects andadvantages as the above-described optical modulator and the opticaldevice can be applied to the projector.

[0053] Further, since the projector has the optical modulator and theoptical device having excellent heat-releasing ability, when a fan isused to cool the optical modulator and the optical device, the size andnoise of the fan can be reduced.

[0054] Further, since the projector has the optical modulator and theoptical device having excellent heat-releasing ability, the light beamfrom the light source can be intensified, thus increasing the brightnessof the image projected on a screen.

BRIEF DESCRIPTION OF THE DRAWINGS

[0055]FIG. 1 is a perspective illustration showing a projector accordingto a first embodiment of the present invention seen from upper frontside thereof;

[0056]FIG. 2 is a perspective view showing the projector from lower rearside thereof;

[0057]FIG. 3 is a perspective view showing the interior of theprojector, which specifically shows the projector shown in FIG. 1 withan upper case being detached;

[0058]FIG. 4 is a perspective view showing the interior of theprojector, which specifically shows the projector shown in FIG. 3 with acontrol board being detached;

[0059]FIG. 5 is an exploded perspective view showing an optical unit ofthe projector;

[0060]FIG. 6 is an illustration schematically showing the optical unit;

[0061]FIG. 7 is a perspective view showing an optical device body of theoptical unit;

[0062]FIG. 8 is an exploded perspective view of a liquid crystal panel;

[0063]FIG. 9 is a perspective view showing a structure of a pair ofsubstrates of the liquid crystal panel;

[0064]FIG. 10 is a cross section of the liquid crystal panel;

[0065]FIG. 11 is a cross section of a liquid crystal panel according toa second embodiment of the present invention;

[0066]FIG. 12 is a cross section of a liquid crystal panel according toa third embodiment of the present invention;

[0067]FIG. 13 is a cross section of a liquid crystal panel according toa fourth embodiment of the present invention;

[0068]FIG. 14 is a cross section of a liquid crystal panel according toa fifth embodiment of the present invention; and

[0069]FIG. 15 is a cross section of a liquid crystal panel according toa sixth embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT(S)

[0070] A first embodiment of the present invention will be descriedbelow with reference to attached drawings.

[0071] [First Embodiment]

[0072] [1. Primary Arrangement of Projector]

[0073]FIG. 1 is a perspective view of a projector 1 seen from upperfront side according to an aspect of the present invention. FIG. 2 is aperspective view of the projector 1 seen from lower rear side.

[0074] As shown in FIGS. 1 and 2, the projector 1 has an approximatelyrectangular parallelepiped exterior case 2 made by injection molding.The exterior case 2 is a casing for housing a body of the projector 1,which includes an upper case 21 and a lower case 22, the cases 21 and 22being attachable and detachable.

[0075] As shown in FIGS. 1 and 2, the upper case 21 includes an upperportion 21A, a lateral portion 21B, a front portion 21C and a rearportion 21D respectively constituting the upper side, lateral side,front side and rear side of the projector 1.

[0076] In the same manner, the lower case 22 includes a lower portion22A, a lateral portion 22B, a front portion 22C and a rear portion 22Drespectively constituting the lower side, lateral side, front side andrear side of the projector 1.

[0077] Accordingly, as shown in FIGS. 1 and 2, the lateral sides 21B and22B of the upper case 21 and the lower case 22 are continuouslyconnected to form a lateral side 210 of the rectangular parallelepipedexterior case 2. Similarly, the front portions 21C and 22C are connectedto form a front side 220, the rear portions 21D and 22D are connected toform a rear side 230, the upper portion 21A forms an upper side 240 andthe lower portion 22A forms a lower side 250.

[0078] As shown in FIG. 1, an operation panel 23 is provided on thefront side of the upper side 240, and a sound-outputting speaker hole240A is formed around the operation panel 23.

[0079] An opening 211 spanning over the two lateral portions 21B and 22Bis formed on the lateral side 210 on the right side seen from frontside. A below-described main board 51 and an interface board 52 areprovided in the exterior case 2 and a connector 51B installed on themain board 51 and a connector 52A installed on the interface board 52are exposed to the outside through an interface panel attached to theopening 211. Exterior electronics etc. are connected to the projectorthrough the connectors 51B and 52A.

[0080] A circular opening 221 spanning between two front portions 21Cand 22C is formed around the operation panel on the right side seen fromthe front side 220. A projection lens 46 is disposed inside the exteriorcase 2 corresponding to the opening 221. At this time, a distal end ofthe projection lens 46 is exposed to the outside from the opening 221and the focusing operation of the projection lens 46 can be manuallyconducted through a lever 46A as a part of the exposed portion.

[0081] An exhaust hole 222 is formed on the front side 220 opposite tothe opening 221. A safety cover 222A is formed on the exhaust hole 222.

[0082] As shown in FIG. 2, a rectangular opening 231 is formed on theright side of the rear side 230 seen from rear side. An inlet connector24 is exposed from the opening 231.

[0083] A rectangular opening 251 is formed at the center of the rightend of the lower side 250 seen from bottom side. A lamp cover 25covering the opening 251 is detachably attached to the opening 251. Anon-illustrated light source lamp can be easily exchanged by detachingthe lamp cover 25.

[0084] A rectangular surface 252 dented inward is formed on the leftrear corner of the lower side 250 seen from bottom side. An intake 252Afor drawing in cooling air from the outside is formed on the rectangularsurface 252. An intake cover 26 covering the rectangular surface isdetachably provided on the rectangular surface 252. An opening 26Acorresponding to the intake 252A is formed on the intake cover 26. Anon-illustrated air filter is provided on the opening 26A to preventinvasion of dust into the interior of the casing.

[0085] A rear leg 2R constituting one of the legs of the projector 1 isformed approximately at the center on the rear side of the lower side250. Further, front legs 2F also constituting the legs of the projector1 are respectively provided on the right and left corners on the frontside of the lower side 250. In other words, the projector 1 is supportedon three points by the rear leg 2R and the two front legs 2F.

[0086] The two front legs 2F is vertically advanceable and retractable,so that the inclination (attitude) of the projector 1 in front and backdirection and right and left direction can be adjusted to adjust theposition of the projection image.

[0087] Further, as shown in FIGS. 1 and 2, a rectangular parallelepipedrecess 253 is formed approximately at the center of the front side ofthe exterior case 2 spanning over the lower side 250 and the front side220. A cover 27 covering the lower side and front side of the recess 253and slidable in front and back direction is provided on the recess 253.A non-illustrated remote controller for remotely controlling theprojector 1 is housed in the recess 253 covered by the cover 27.

[0088]FIGS. 3 and 4 are perspective view showing the interior of theprojector 1. Specifically, FIG. 3 is an illustration showing the uppercase 21 being removed from FIG. 1. FIG. 4 is an illustration with acontrol board 5 being removed from FIG. 3.

[0089] As shown in FIGS. 3 and 4, the exterior case has a power sourceunit 3 disposed along the rear side and extending in right and leftdirection, an optical unit 4 disposed on the front side of the powersource unit 3 as a planarly-viewed L-shaped optical system and thecontrol board 5 as a controller disposed on the upper right side of theunits 3 and 4. The components 3 to 5 constitute the primary portion ofthe projector 1.

[0090] The power source unit 3 has a power source 31 and anon-illustrated lamp driving circuit (ballast) disposed below the powersource 31.

[0091] The power source 31 supplies the electric power from the outsideto the lamp driving circuit, the circuit board 5 etc. through anon-illustrated power cable connected to the inlet connector.

[0092] The lamp driving circuit supplies electric power fed by the powersource 31 to a light source lamp (not shown in FIGS. 3 and 4) of theoptical unit 4, which is electrically connected to the light sourcelamp. The lamp driving circuit is, for instance, constructed by wiringon a board.

[0093] The power source 31 and the lamp driving circuit are verticallyarranged approximately in parallel, which occupy the space extending inright and left direction on the rear side of the projector 1.

[0094] The surroundings of the power source 31 and the lamp drivingcircuit are covered with a metal shield 31A such as aluminum with rightand left sides thereof being opened.

[0095] The shield 31A works as a duct for guiding the cooling air andprevents leakage of the electromagnetic noise generated by the powersource 31 and the lamp driving circuit toward the outside.

[0096] As shown in FIG. 3, the control board 5 is disposed to cover theupper side of the units 3 and 4, which includes the main board 51including a CPU and the connector 51B and the interface board 52disposed below the main board 51 and including the connector 52A.

[0097] In the control board 5, the CPU on the main board 51 controls aliquid crystal panel 441 of the below-described optical device inaccordance with the image information inputted through the connectors51B and 52A.

[0098] The surroundings of the main board 51 is covered with a metalshield 51A. Though not clearly shown in FIG. 3, the main board 51 abutsto an upper end 472A of an upper inner case 472 of the optical unit 4.

[0099] [2. Detailed Construction of Optical Unit]

[0100]FIG. 5 is an exploded perspective view showing the optical unit 4.FIG. 6 is a schematic illustration of the optical unit 4.

[0101] As shown in FIG. 6, the optical unit 4 is a unit for opticallyprocess the light beam irradiated by a light source lamp 416 of a lightsource 411 to form an optical image corresponding to the imageinformation and project the optical image in an enlarged manner, whichincludes an integrator illuminating optical system 41, a colorseparating optical system 42, a relay optical system 43, an opticaldevice 44, the projection lens 46 as a projection optical system, and aninner case 47 made of synthetic resin for housing the optical components41 to 44 and 46 (FIG. 5).

[0102] The integrator illuminating optical system 41 is a system forsubstantially uniformly illuminating the image formation area of thethree liquid crystal panels 441 constituting the optical device 44(respectively referred to as liquid crystal panel 441R, 441G and 441Bfor every color lights of red, green and blue), which includes the lightsource 411, a first lens array 412, a second lens array 413, apolarization converter 414 and a superposing lens 415.

[0103] The light source 411 has the light source lamp 416 as a radiationlight source and a reflector 417, which changes the radial light beamirradiated by the light source lamp 416 into a parallel light beam bythe reflector 417 to emit the parallel light beam toward the outside.

[0104] The first lens array 412 is a plurality of small lenses arrangedin matrix, the lenses having substantially rectangular profile viewedfrom optical axis direction. The respective lenses split the beamemitted from the light source lamp 416 into a plurality of sub-beams.The profile of the respective lenses is approximately similar to theconfiguration of the image formation area of the liquid crystal panel441. For instance, when the aspect ratio (ratio of horizontal andvertical dimensions) of the liquid crystal panels 441 is 4:3, the aspectratio of the respective lenses is also set as 4:3.

[0105] The second lens array 413 has approximately the same arrangementas the first lens array 41/2*Where the small lenses are disposed inmatrix. The second lens array 413 as well as the superposing lens 415focuses the image from the respective small lenses of the first lensarray 412 onto the liquid crystal panel 441.

[0106] The polarization converter 414 is disposed between the secondlens array 413 and the superposing lens 415. The polarization converter414 converts the light from the second lens array 413 to uniformpolarized light in order to enhance light utilization efficiency in theoptical device 44.

[0107] The color separating optical system has two dichroic mirrors 421and 422 and a reflection mirror 423, the dichroic mirrors 421 and 422separating the plurality of sub-beams irradiated by the integratorilluminating optical system 41 into three color lights of red (R), green(G) and blue (B).

[0108] The relay optical system 43 has incident-side lens 431, a relaylens 43 and reflection mirrors 432 and 434, and introduces the red colorlight separated by the color separating optical system 42 onto theliquid crystal panel 441R.

[0109] At this time, the red light component and the green lightcomponent of the light beam irradiated from the integrator illuminatingoptical system 41 are transmitted through the dichroic mirror 421 of thecolor separating optical system 42 and the blue light component isreflected by the dichroic mirror 421. The blue light reflected by thedichroic mirror 421 is reflected by the reflection mirror 423, whichreaches to the liquid crystal panel 441B for blue-color through a fieldlens 418. The field lens 418 converts the respective sub-beams emittedfrom the second lens array 413 into a light beam parallel to centralaxis (main beam) thereof. The field lenses 418 provided in front of theother liquid crystal panels 441G and 441R function in the same manner.

[0110] In the red light and the green light transmitted through thedichroic mirror 421, the green light is reflected by the dichroic mirror422 to reach the liquid crystal panel 441G for green color through thefield lens 418. On the other hand, the red color transmits through thedichroic mirror 422 to pass the relay optical system 43 and reach theliquid crystal panel 441R for red color through the field lens 418.

[0111] Incidentally, the relay optical system 43 is used for the redcolor light in order to prevent decrease in utilization efficiency oflight on account of light diffusion caused by longer length of theoptical path of the red light than the length of the optical path of theother color lights, in other words, in order to directly transmit thesub-beam incident on the incident-side lens 431 to the field lens 418.Incidentally, though the red light passes through the relay opticalsystem 43, blue light may pass through the relay optical system 43instead of red light.

[0112] The optical device 44 is for modulating the incident light beamin accordance with image information to form a color image, which hasthree incident-side polarization plates 442, a vision-angle-correctingfilter plate 448 for correcting vision angle, the liquid crystal panels441R, 441G and 441B disposed on the after-stage of the respectiveincident-side polarization plates 442 as optical modulators, anirradiation-side polarization plate 443 disposed on the after-stage ofthe respective incident-side polarization plates 442, and a crossdichroic prism 444 as a color combining optical system. Detailedstructure of the liquid crystal panel 441 (441R, 441G and 441B) will bedescribed below.

[0113] In the optical device 44, the color lights separated by thecolor-separating optical system 42 are modulated by the three crystalpanels 441R, 441G and 441B, the incident-side polarization plate 442,the vision-angle-correcting filter plate 448 and the irradiation-sidepolarization plate 443 in accordance with image information to form anoptical image.

[0114] The incident-side polarization plate 442 transmits only apolarized light of a predetermined direction among the respective colorlights separated by the color separating optical system and absorbs theother light beam.

[0115] The irradiation-side polarization plate 443 is constructed in anapproximately the same manner as the incident-side polarization plate442, which transmits only a polarized light of a predetermined directionamong the light beam irradiated by the liquid crystal panels 441 (441R,441G and 441B) and absorbs the other light beam.

[0116] The polarization axes of the incident-side polarization plate 442and the irradiation-side polarization plate 443 are set orthogonal witheach other.

[0117] The cross dichroic prism 444 combines the optical imageirradiated by the irradiation-side polarization plate 443 and modulatedfor respective color lights to form a color image.

[0118] A dielectric multi-layer film for reflecting red color light anda dielectric multi-layer film for reflecting blue color light are formedalong boundary of four right-angled prisms of the cross dichroic prism444, the dielectric multi-layer films combining three color lights.

[0119] The vision-angle-correcting filter plate 448 is constructed byadhering a vision-angle-correcting film for correcting vision angle on atransparent substrate such as sapphire glass.

[0120] The above-described liquid crystal panels 441, theirradiation-side polarization plate 443 and the cross dichroic prism 444are constructed as an integrated unit of optical device body 45. FIG. 7is a perspective view showing the optical device body 45.

[0121] The optical device body 45 has the cross dichroic prism 444, afixing member 447 made of synthetic resin and fixed on the upper side ofthe cross dichroic prism 444, a metal polarization plate holding plate446 attached to the light-incident side of the cross dichroic prism 444for holding the irradiation-side polarization plate 443, and the liquidcrystal panels 441 (441R, 441G and 441G) held by four pins 445 made oftransparent resin attached to the light-incident side of thepolarization plate holding plate 446.

[0122] A predetermined gap is secured between the polarization plateholding plate 446 and the liquid crystal panel 441, so that the coolingair can flow through the gap.

[0123] The optical device body 45 is screwed to the lower inner case 471through a circular hole 447B of four arms 447A formed on the fixingmember 447.

[0124] [3. Detailed Structure of Liquid Crystal Panel]

[0125] The structure of the liquid crystal panel 441 will be describedbelow with reference to FIGS. 8 to 10. As shown in FIG. 8, the liquidcrystal panel 441 has an optical modulator body 500 and a holding frame510 for holding and fixing the optical modulator body 500.

[0126] The optical modulator body 500 has a pair of substrates 501A and501B made of glass etc. and dust-proof glasses 502A and 502B attached onthe pair of substrates 501A and 501B.

[0127] The pair of substrates 501A and 501B are attached with apredetermined space secured therebetween through a sealing member (notshown), and liquid crystal as an electrooptic material is filled betweenthe substrates 501A and 501B.

[0128] As shown in FIG. 9, a plurality of data lines 501C mutuallyaligned in parallel, a plurality of scan lines 501D arranged in adirection orthogonal with the plurality of data lines, and a switchingelement 501F such as a TFT element disposed between picture electrodesmade of transparent conductive material such as ITO (Indium Tin Oxide)are formed on the (first) substrate 501A of the pair of substrates. Anopposing electrode 501G and a black mask 501H corresponding to thepicture electrode are formed on the inner surface of the other (second)substrate (501B), thereby structuring active-matrix liquid crystalpanel.

[0129] The light beam is incident on the pair of substrates 501A and501B from the side of the second substrate 501B and the light beam isirradiated from the side of the first substrate 501A.

[0130] As shown in FIG. 10, the dust-proof glasses 502A and 502B areadhered on the outer surface of the pair of substrates 501A and 501B (onthe light-incident and light-irradiation side). The dust-proof glasses502A and 502B covers the outer surface of the substrate to preventadhesion of dust on the substrate. When dust is adhered on the outersurface of the dust-proof glasses 502A and 502B, since the dust is outof focus, the dust is not displayed as a shadow on the projection image.

[0131] The dust-proof glasses 502A and 502B are constructed by, forinstance, sapphire, quartz, crystal, fluorite and so on. Following Table1 shows the characteristics (thermal conductivity, linear expansioncoefficient) of the respective materials. TABLE 1 Thermal ConductivityLinear Expansion Coefficient W/m · K *10⁻⁶/K Sapphire 42 5.3 Quartz 1.20.58 Crystal 9.3 6.8 (parallel to optical axis) 5.4 12.2 (perpendicularto optical axis)

[0132] The outer diameter of the dust-proof glass 502A adhered on thefirst substrate 501A is smaller than the outer diameter of the firstsubstrate 501A.

[0133] The dust-proof glass 502B adhered on the second substrate 501Babuts to an accommodating portion 511 of the below-described holdingframe 510.

[0134] The holding frame 510 has the accommodating portion 511 foraccommodating and holding the optical modulator body 500 and a fixingplate 512 for pressing the accommodated optical modulator body 500toward the accommodating portion 511 from a light-irradiation side.

[0135] The accommodating portion 511 is an approximately rectangularframe having an opening 511A corresponding to the image formation areaof the substrates 501A and 501B. An attachment hole for the pins 445 ofthe polarization plate holding plate 446 to be inserted is formed on thefour corners of the accommodating portion 511 (see FIG. 7). A hookstopper 511B to be engaged with the fixing plate 512 is formedapproximately at the center of the lateral side of the accommodatingportion 511.

[0136] Similar to the accommodating portion 511, the fixing plate 512 isan approximately rectangular frame having an opening 512A correspondingto the image formation area of the substrates 501A and 501B. A hook 512Bcorresponding to the hook stopper 511B is formed on the fixing plate512. A frame member 512C projects on the light-incident side of thefixing plate 512 around the opening 512A. The fixing plate 512 and theframe member 512C may be integrated by bonding with an adhesive etc., oralternatively, may be integrated by welding etc. The fixing plate 512and the frame member 512C may be formed as a unitary molding componentformed by injection molding etc. of the same material.

[0137] The frame member 512C has an outer profile greater than the outerprofile of the dust-proof glass 502A. A step portion 512D is provided onthe distal end of the inner periphery of the frame member 512C so thatthe end of the outer circumference of the substrate 501A is fitted. Theheight of the step portion 512D is slightly greater than the thicknessof the dust-proof glass 502A. In other words, when the optical modulatorbody 500 is accommodated and held in the holding frame 510, apredetermined gap is formed between the inner periphery of the framemember 512C and the outer periphery of the dust-proof glass 502A andbetween the light-incident side of the fixing plate 512 and thelight-irradiation side of the dust-proof glass 502A, as shown in FIG.10.

[0138] The outer periphery of the frame member 512C is smaller than theinner profile of the accommodating portion 511. In other words, when theoptical modulator body 500 is accommodated and held in the holding frame510, a predetermined gap is formed between the outer circumference ofthe frame member 512C and the inner circumference of the accommodatingportion 511 as shown in FIG. 10.

[0139] The above-described accommodating portion 511 and the fixingplate 512 are made of metal, e.g. steel-nickel alloy such as Invar and42Ni—Fe, magnesium alloy and aluminum alloy, or heat-conductive resin.Incidentally, the accommodating portion 511 and the fixing plate 512 maybe made of the same material or different material. The fixing plate 512and the frame member 512C may be made of the same material or differentmaterial. When the accommodating portion 511, the fixing plate 512 andthe frame member 512C are made of the same material, since the dimensionvariation (expansion and contraction) of the respective componentscaused by heat becomes the same, reliability of the liquid crystal panel441 can be greatly improved. The characteristics (thermal conductivityand linear expansion coefficient) of the respective components are shownin the Table 2 below. TABLE 2 Linear Thermal Expansion ConductivityCoefficient* W/m · K 10⁻⁶/K Invar (NI36-Fe) 10.15 15 42Fe—Ni 12.6 4.5Magnesium Alloy (AZ91D) 72 25 Aluminum Alloy (380AL) 96 21.8Heat-Conductive Resin 15 4 (Cool Poly D2 (tradename)) (parallel to fiberdirection) 10 (perpendicular to fiber direction)

[0140] Such liquid crystal panel 441 is assembled as follows.

[0141] Initially, an adhesive is coated on the inner circumference ofthe accommodating portion of the holding frame 510. Next, the opticalmodulator body 500 is accommodated in the accommodating portion 511 fromthe side of the dust-proof glass 502B. Further, the first substrate 501Ais fitted to the step portion 512D of the frame member 512C of thefixing plate 512. Then, an adhesive is filled in a space formed betweenthe inner periphery of the frame member 512C and the outer periphery ofthe dust-proof glass 502A, between the light-incident side of the fixingplate 512 and the light-irradiation side of the dust-proof glass 502Aand between the outer circumference of the frame member 512C and theinner circumference of the accommodating portion 511. Subsequently, thehook 512B of the fixing plate 512 is engaged with the hook stopper 511Bof the accommodating portion 511 to press the optical modulator body 500to the accommodating portion 511.

[0142] A thermosetting adhesive or a photo-curing adhesive can be usedas the above adhesive. The adhesive having excellent thermalconductivity may be an adhesive containing metal such as silver, silverpalladium and copper or carbon.

[0143] According to the present embodiment, following advantages can beobtained.

[0144] (1) Since the frame member 512C made of heat-conductive materialtouching with the first substrate 501A is disposed on the outerperiphery of the first substrate 501A of the liquid crystal panel 441,the heat generated on the first substrate 501A can be efficientlytransmitted to the frame member 512C. Since the frame member 512C isintegrated with the fixing plate 512, sufficient contact area of theframe member 512C and the fixing plate 512 can be secured, thusreleasing the heat generated on the first substrate 501A to the outsidethrough the heat conduction channel from the frame member 512C to thefixing plate 512. Accordingly, excellent heat-releasing ability of theoptical modulator body 500 can be secured, thus lengthening the life ofthe liquid crystal panel 441. Further, there is no need for thicken thefixing plate 512 to increase the heat capacity, thereby preventingdeterioration of image quality.

[0145] (2) Since the fixing plate 512 and the frame member 512C are madeof heat-conductive material having especially high thermal conductivity,the heat-conductive material including heat-conductive metal such assteel-nickel alloy including Invar and 42Ni—Fe, magnesium alloy andaluminum alloy and heat-conductive resin including polycarbonate,polyphenylene sulfide and liquid crystal resin containing carbon fillersuch as carbon fiber and carbon nanotube, heat-releasing ability of thefirst substrate 501A can be further enhanced by the heat conductionchannel from the frame member 512C to the fixing plate 512.

[0146] (3) When the thermal conductivity of the fixing plate 512 and theframe member 512C is more than 10W/(m·K), the heat generated on thefirst substrate 501A can be rapidly released through the heat conductionchannel from the frame member 512C to the fixing plate 512. Suchmaterial may be selected from various materials shown in Table 2, sothat the liquid crystal panel 441 can be optimally designed.

[0147] (4) Since a predetermined gap is formed on the outercircumference of the frame member 12C and the inner circumference of theaccommodating portion 511, even when the frame member 512C and theaccommodating portion 511 are made of different materials, mechanicalinterference between the frame member 512C and the accommodating portion511 on account of variation of dimension (expansion and contraction)caused by heat can be prevented. Accordingly, distortion on the liquidcrystal panel 441 caused by the heat generated on the optical modulatorbody 500 can be avoided, and deterioration in image quality on accountof change in the shape of the liquid crystal sealed between the pair ofsubstrates 501A and 501B can be prevented.

[0148] (5) Since the data line 501C and the scan line 501D are formed onthe first substrate 501A, which absorbs the heat generated byirradiation of the light beam from the light source, the temperature ofthe first substrate 501A is likely to be raised. Since the frame member512C is in direct contact with the first substrate 501A, theheat-releasing ability of the first substrate 501A can be furtherenhanced.

[0149] (6) Since the dust-proof glass 502A and 502B are made of materialsuch as sapphire, quartz, crystal, and fluorite, having high thermalconductivity, the heat-releasing ability from the first and the secondsubstrates 501A and 501B on which the dust-proof glasses 502A and 502Bare adhered can be further improved.

[0150] (7) Since a heat-conductive adhesive is filled in the gap formedbetween the outer circumference of the frame member 512C and the innercircumference of the accommodating portion 511, the adhesive assistsheat-conductance between the respective components, so that heatconduction channel from the frame member 512C to the accommodatingportion 511 as well as from the frame member 512C to the fixing plate512 can be secured, thus further enhancing heat-releasing ability of thefirst substrate 501A.

[0151] (8) Since the heat-conductive adhesive is filled between theframe member 512C and the combination of the dust-proof glass 502A andthe first substrate 501A, the adhesive assists heat-conductance betweenthe respective components so that the heat generated on the firstsubstrate 501A can be rapidly released through the heat conductionchannel from the frame member 512C to the fixing plate 512.

[0152] (9) Since the adhesive filled in the gap formed between the outercircumference of the frame member 512C and the inner circumference ofthe accommodating portion 511 and between the frame member 512C and thecombination of the dust-proof glass 502A and the first substrate 501Acontains metal such as silver, silver palladium and copper or carbon,the metal contained in the adhesive thermally couples the componentssandwiching the adhesive, thereby further accelerating heat-conductancebetween the components.

[0153] (10) Since the linear expansion coefficient of the fixing plate512 and the frame member 512C approximates to the linear expansioncoefficient of the dust-proof glass 502A and the first substrate 501Awhen the linear expansion coefficient of the fixing plate 512 and theframe member 512C is not more than 6*10⁻⁶/K, dimension variation(expansion and contraction) between the fixing plate 512 and the framemember 512C and the dust-proof glass 502A and the first substrate 501Acaused by the heat of the respective components can be madeapproximately equal. Accordingly, distortion generated on the liquidcrystal pane 1441 on account of the heat generated on the opticalmodulator body 500 can be prevented and deterioration of image qualityon account of change in the shape of the liquid crystal sealed betweenthe pair of substrates 501A and 501B can be prevented. Such material maybe selected from various materials shown in Table 2, so that the liquidcrystal panel 441 can be optimally designed.

[0154] (11) Since the irradiation-side polarization plate 443 and theprism 444 are attached to the light-irradiation side of the liquidcrystal panel 441, the heat cannot be efficiently released on thelight-irradiation side of the liquid crystal panel 441. In the presentembodiment, since the fixing plate 512 integrated with the frame member512C is disposed on the side of the first substrate 501A disposed on thelight-irradiation side of the liquid crystal panel 441, theheat-releasing ability of the light-irradiation side of the liquidcrystal panel 441 can be improved.

[0155] (12) The black mask 501H is formed on the second substrate 501Band the second substrate 501B generates heat by the black mask 501Habsorbing light beam, the heat being released after being transmitted tothe accommodating portion 511 through the dust-proof glass 502B. In thepresent embodiment, since the accommodating portion 511 is made ofheat-conductive material similar to the fixing plate 512 and the framemember 512C, the heat-releasing ability of the second substrate 501B canbe improved.

[0156] (13) The step portion 512D is formed on the frame member 512C andthe lateral side and the light irradiation side of the first substrate501A are in contact with the step portion 512D. Accordingly, largecontact area can be secured between the frame member 512C and the firstsubstrate 501A, thus enhancing heat-conductance efficiency to the framemember 512C.

[0157] (14) The height of the step portion 512D is slightly greater thanthe thickness of the dust-proof glass 502A. Accordingly, the fixingplate 512 and the frame member 512C are not in contact with thedust-proof glass 502A, so that the dust-proof glass 502A is not likelyto be damaged.

[0158] (15) Since the projector 1 has the above-described liquid crystalpanel 441, the light beam from the light source 411 can be intensified,thus increasing the brightness of the image projected on the screen.

[0159] (16) Since the projector 1 has the above-described liquid crystalpanel 441, when a fan is used for cooling the liquid crystal panel 441,the size of the fan can be reduced, thereby reducing the noise from thefan.

[0160] [Second Embodiment]

[0161] Next, a second embodiment of the present invention will bedescribed below. Incidentally, the same reference numeral will beattached to the same components as in the above to omit the descriptionthereof.

[0162] In the first embodiment, the frame member 512C of the fixingplate 512 is not in contact with the dust-proof glass 502A but is incontact with the first substrate 501A.

[0163] In contrast thereto, liquid crystal panel 441′ according to thesecond embodiment has a frame member 612C of a fixing plate 612 not incontact with the first substrate 501A but in contact with the dust-proofglass 502A as shown in FIG. 11.

[0164] The frame member 612C has approximately the same profile as theouter profile of the dust-proof glass 502A, where the dust-proof glass502A is fitted. A step portion 612D is formed on the distal end of theinner periphery of the frame member 612C approximately in the samemanner as the step portion 512D of the frame member 512C of the firstembodiment, the height of the step portion 612D being slightly smallerthan the thickness of the dust-proof glass 502A. In other words, asshown in FIG. 11, when the optical modulator body 500 is accommodatedand held within the holding frame 510, a gap is formed between the outercircumference of the frame member 612C and the inner side of theaccommodating portion 511 and also a predetermined gap is formed betweenthe step portion 612D of the frame member 612C and the light irradiationside and lateral side of the substrate 501A. When the liquid crystalpanel 441′ is assembled, an adhesive having good thermal conductivitydescribed in the first embodiment is filled in the gaps.

[0165] According to the second embodiment, following advantages as wellas the advantages (2) to (4), (6) to (12), (15) and (16) of the firstembodiment can be obtained.

[0166] (17) The heat transferred from the first substrate 501A to thedust-proof glass 502A is transferred to the frame member 612C, which isreleased to the outside though the heat conduction channel from theframe member 612C to the fixing plate 612. Accordingly, even when theframe member 612C is in contact with the dust-proof glass 502A, the heatcan be efficiently released.

[0167] (18) Since the frame member 612C only abuts to the dust-proofglass 502A, the first substrate 501A is not damaged by the frame member612C.

[0168] (19) Since the frame member 612C is in contact with the lateralside and the light irradiation side of the dust-proof glass 502A, largecontact area against the dust-proof glass 502A can be secured, thusefficiently releasing the heat of the dust-proof glass 502A.

[0169] [Third Embodiment]

[0170] Next, a third embodiment of the present invention will bedescribed below.

[0171] As shown in FIG. 12, a frame member 712C of the fixing plate 712of a liquid crystal panel 441″ of the present embodiment is in contactwith the first substrate 501A and the dust-proof glass 502A.

[0172] Unlike the above embodiments, the frame member 712C has no stepportion. The inner periphery of the frame member 712C is in contact withthe lateral side of the dust-proof glass 502A and the projecting side ofthe frame member 712C is in contact with the light-irradiation side ofthe substrate 501A.

[0173] According to the third embodiment, following advantages as wellas the advantages (1) to (12), (15) and (16) of the first embodiment canbe obtained.

[0174] (20) Since the frame member 712C is in contact with the firstsubstrate 501A and the dust-proof glass 502A, the heat can be releaseddirectly from the first substrate 501A and indirectly from thedust-proof glass 502A. Accordingly, heat-releasing ability of the firstsubstrate 501A can be further enhanced.

[0175] (21) Since there is no step portion on the frame member 712Cunlike the above-described embodiments, the frame member 712C can bemore easily manufactured by separately when the fixing plate 712 and theframe member 712C are separately produced.

[0176] [Fourth Embodiment]

[0177] Next, a fourth embodiment of the present invention will bedescribed below. In the above-described first to the third embodiments,the fixing plate and the frame member are integrated. In contrastthereto, as shown in FIG. 13, a frame member 20 of a liquid crystalpanel 1441 of the fourth embodiment is constructed as a body independentof the fixing plate 512.

[0178] The frame member 520 is made of heat-conductive material and isprovided on the outer periphery of the first substrate 501A. Theheat-conductive material may be magnesium, aluminum, titanium and alloythereof or a heat-conductive resin etc.

[0179] The frame member 520 is in contact with the fixing plate 512 ofthe holding frame 510. A cut 521 for the outer edge of the firstsubstrate 501A to be fitted is formed on the inner side of the framemember 520 and the cross section of the frame member 520 is arranged inL-shape. Accordingly, the frame member 520 is in contact with thelight-irradiation side and lateral side of the first substrate 501A.

[0180] The light-irradiation surface of the frame member 520 slightlyprojects toward the light-irradiation side relative to thelight-irradiation surface of the dust-proof glass 502A.

[0181] Further, slight gap is formed between the frame member 520 andthe dust-proof glass 502A and a heat-conductive adhesive is filled inthe gap.

[0182] The holding frame 510 has the accommodating portion 511 foraccommodating and holding the frame member 520 and the optical modulatorbody 500, and the fixing plate 512 for pressing the accommodated framemember 520 and the optical modulator body 500 from the light-irradiationside.

[0183] The accommodating portion 511 is made of the same heat-conductivematerial as the frame member 520 such as magnesium, aluminum, titaniumand alloy thereof or a heat-conductive resin etc.

[0184] The fixing plate 512 is also formed in a frame shape similarly tothe accommodating portion 511 and the hook 512B corresponding to thehook stopper 511B is formed on the fixing plate 512. The opening 512Acorresponding to the image formation area of the substrates 501A and501B is formed on the fixing plate 512.

[0185] The liquid crystal panel 1441 is assembled as follows.

[0186] Initially, thermosetting adhesive having excellent thermalconductivity is coated on the inner circumference of the accommodatingportion 511 of the holding frame 510. Next, the optical modulator body500 is accommodated in the accommodating portion 511 from the side ofthe dust-proof glass 502B. Further, the frame member 520 is attached tothe first substrate 501A and heat-conductive adhesive is filled in thegap between the frame member 520 and the dust-proof glass 502A.Subsequently, the hook 512A of the fixing plate 512 is engaged with thehook stopper 511B of the accommodating portion 511 to press and fix theoptical modulator body 500 to the accommodating portion 511.

[0187] According to the present embodiment, since the fixing plate 512and the frame member 520 are constructed as independent components,positioning process required in molding a unitary component can besimplified. Further, since the fixing plate 512 and the frame member 520are separate components, the fixing plate 512 and the frame member 520can be exchanged as necessary.

[0188] Further, since the heat-conductive adhesive filled in the gapbetween the frame member 520 and the dust-proof glass 502A permeatesthough the space between the inner side of the accommodating portion 511of the holding frame 510 and the frame member 520, thermal conductivitycan be further enhanced.

[0189] [Fifth Embodiment]

[0190] Next, a fifth embodiment of the present invention will bedescribed below.

[0191] In a liquid crystal panel 1441 ′ according to the fifthembodiment of the present invention, as shown in FIG. 14, instead of theintegrated fixing plate 612 and the frame member 612C of the secondembodiment, a frame member 620 is constructed as a component independentof the fixing plate 512. The frame member 620 is not in contact with thefirst substrate 501A but is in contact with the dust-proof glass 502A.

[0192] The frame member 620 has a cut 621 for the outer edge of thefirst substrate 501A to be fitted and a cut 622 for the outer edge ofthe dust-proof glass 502A to be fitted.

[0193] The cut 622 of the frame member 620 is in contact with thedust-proof glass 502A. In other words, the frame member 620 is incontact with the light-irradiation side and the lateral side of thedust-proof glass 502A.

[0194] On the other hand, a gap is retained between the cut 621 of theframe member 620 and the first substrate 501A and heat-conductiveadhesive is filled in the gap.

[0195] A step portion 623 is formed on the light-irradiation surface ofthe frame member 620 and the fixing plate 512 of the holding frame 510is in contact with the step portion 623.

[0196] According to the fifth embodiment, as well as the advantages ofthe second embodiment, since the fixing plate 512 and the frame member620 are made independent, positioning process required in molding aunitary component can be simplified. Further, since the fixing plate 512and the frame member 620 are separate components, the fixing plate 512and the frame member 620 can be exchanged as necessary.

[0197] [Sixth Embodiment]

[0198] Next, a sixth embodiment of the present invention will bedescribed below.

[0199] As shown in FIG. 15, in a liquid crystal panel 1441 ′ accordingto the fifth embodiment of the present invention, instead of theintegrated fixing plate 712 and the frame member 712C of the thirdembodiment, a frame member 720 is constructed as a component independentof the fixing plate 512 and is in contact with the first substrate 501Aand the dust-proof glass 502A.

[0200] Unlike the fourth and the fifth embodiments, there is no cut onthe frame member 720. The frame member 720 is disposed at a portion onthe light-irradiation surface of the first substrate 501A on which thedust-proof glass 502A is not attached.

[0201] According to the sixth embodiment, as well as the advantages ofthe third embodiment, since the fixing plate 512 and the frame member720 are made independent, positioning process required in molding aunitary component can be simplified. Further, since the fixing plate 512and the frame member 720 are separate components, the fixing plate 512and the frame member 720 can be exchanged as necessary.

[0202] [Modifications]

[0203] Incidentally, the scope of the present invention is notrestricted to the above-described embodiments, but includesmodifications and improvements as long as an object of the presentinvention can be achieved.

[0204] For instance, though the frame members 512C, 612C and 712Cintegrated with the fixing plates 512, 612 and 712 of the holding frame510 are formed along the opening 512A, such arrangement is not limiting.For instance, the frame members 512C, 612C and 712C may be integratedwith a part of the periphery of the opening 512A, e.g. four corners ofthe periphery of the opening 512A.

[0205] Though the accommodating portion 511 of the holding frame 510 ismade of heat-conductive material similar to the fixing plates 512, 612and 712 and the frame members 512C, 612C and 712C in the aboveembodiments, the accommodating portion 511 may be constructed by othermaterial such as a plastic.

[0206] Though the accommodating portion 511 of the holding frame 510 ismade of heat-conductive material similar to the fixing plates 520, 620and 720 and the frame members 512C, 612C and 712C in the aboveembodiments, the frame members 520, 620 and 720 may be constructed byother material such as a plastic.

[0207] Though the frame members 520, 620 and 720 are made of magnesium,aluminum, titanium and alloy thereof or heat-conductive resin etc., itis only required that the frame members 520, 620 and 720 are made ofheat-conductive material, which may be other heat-conductive materialsuch as copper. However, since magnesium, aluminum, titanium and alloythereof or heat-conductive resin has extremely high thermalconductivity, the heat-releasing ability of the first substrate 501A canbe enhanced by using magnesium, aluminum, titanium and alloy thereof orheat-conductive resin.

[0208] Though the optical modulator body 500 has the dust-proof glasses502A and 502B in the above-described embodiments, the dust-proof glasses502A and 502B may be omitted.

[0209] Though the frame members 520, 620 and 720 are in contact with thefixing plate 512 of the holding frame 510, the frame members 520, 620and 720 may be in contact with the accommodating portion 511. Accordingto such arrangement, the heat of the first substrate 501A can bereleased from the accommodating portion 511.

What is claimed is:
 1. An optical modulator that modulates a light beamirradiated by a light source in accordance with image information,comprising: an optical modulator body having a pair of transparentsubstrates between which an electrooptic material is sealed; a holdingframe having an accommodating portion that accommodates the opticalmodulator body and a fixing plate that presses and holds the opticalmodulator body within the accommodating portion; and a frame member madeof a heat-conductive material and provided on an outer periphery of afirst substrate of the pair of substrates disposed on the side of thefixing plate, the frame member being in contact with the accommodatingportion and/or the fixing plate.
 2. The optical modulator according toclaim 1, wherein the fixing plate and the frame member is integrallyformed.
 3. The optical modulator according to claim 1, wherein thefixing plate and the frame member is made of a heat-conductive metal ora heat-conductive resin.
 4. The optical modulator according to claim 3,wherein the thermal conductivity of the heat-conductive metal and theheat-conductive resin is not less than 10W/(m·K).
 5. The opticalmodulator according to claim 1, wherein the frame member is accommodatedand held in the accommodating portion together with the opticalmodulator body and a predetermined gap is secured between the outercircumference of the frame member and the inner circumference of theaccommodating portion.
 6. The optical modulator according to claim 1,wherein a dust-proof glass that prevents adhesion of dust on the outersurface of the substrate is closely attached on the outer surface of thefirst substrate, and wherein the frame member is in contact with thedust-proof glass and/or the first substrate.
 7. The optical modulatoraccording to claim 6, wherein the dust-proof glass is made of any one ofmaterials selected from the group consisting of sapphire, quartz,crystal or fluorite.
 8. The optical modulator according to claim 5,wherein a heat-conductive adhesive is filled in the predetermined gapand between the frame member and the dust-proof glass and/or the firstsubstrate.
 9. The optical modulator according to claim 8, wherein theadhesive contains a metal material.
 10. The optical modulator accordingto claim 8, wherein a linear expansion coefficient of the fixing plateand the frame member is not more than 6*10⁻⁶/K.
 11. The opticalmodulator according to claim 1, wherein the plurality of data linesarranged mutually in parallel, a plurality of scan lines arranged in adirection orthogonal with the plurality of data lines, a pictureelectrode, and a switching element disposed between the data and thescan lines and the picture electrode are formed on the first substrate.12. The optical modulator according to claim 1, wherein the firstsubstrate is disposed on a light-irradiation side of the opticalmodulator body.
 13. An optical device, comprising: a plurality ofoptical modulators that modulates a plurality of color lights inaccordance with image information respectively for the color lights; anda color combining optical device that combines the color lightsmodulated by the respective optical modulators, wherein the opticalmodulator is the optical modulator according to claim
 1. 14. A projectorthat forms an optical image by enlarging and projecting a light beamirradiated by a light source after modulating the light beam,comprising: an optical modulator according to claim 1 or an opticaldevice according to claim 13.